Tube bending tool



G. E. FRANCK TUBE BENDING TOOL Set 11, 1956 Filed Dec. 2'7, 1951 P 1956 G. E. FRANCK 2,762,415

. TUBE BENDING TOOL Filed Dec. 27, 1951 2 Sheets-Sheet 2 INVENTOR.

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George E. Franck, Riverside, Ill., assignor to The Imperial Brass Manufacturing Company, a corporation of Illinois Application December 27, 1951, Serial No. 263,673

3 Claims. (Cl. 153-40) This invention relates to a tube bending tool and more particularly to a tube bending tool which is admirably suited for bending resilient types of tubing, such as stainless steel and the harder grades of copper tubing.

It is the general object of this invention to produce a new and improved tube bending tool.

A further object of the invention is to produce a tube bending tool of lightweight and yet sturdy construction.

Still another object of the invention is to produce a tube bending tool provided with a gear, together with means for securing any one of a plurality of mandrels of different sizes to the gear and provided with a shoe holding member adapted to hold any one of a plurality of shoes of different sizes immediately adjacent a mandrel for cooperation therewith to produce a tube bending tool capable of handling tubes of various diameters.

Other and further objects and features of the inven tion will be readily apparent from the following description and drawings, in which:

Fig. l is a top plan view of a tube bending tool embodying the invention;

Fig. 2 is a side elevational view of the device shown in Fig. 1;

Fig. 3 is a top plan view of the mandrel and shoe portion of the tube bending tool showing its use with mandrels and shoes of different sizes; and

Figs. 4, 5 and 6 are sectional views taken along lines 4, 5-5 and 6-6, respectively, of Fig. 1.

While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail one specific embodiment, with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated. The scope of the invention will be pointed out in the appended claims.

Referring now to the drawings, the tube bending tool of this invention includes a substantially rectangular body member 10 preferably constructed of a lightweight material, such as aluminum alloy. Secured in an opening 11 in the body member is a bearing stud 12 (Fig. 4) provided with a serrated exterior surface 13 press fitted in the opening to hold the stud therein. The stud is formed with a first reduced portion 14 which rotatably supports a gear 15 on the body member. The gear is adapted to hold any one of a plurality of mandrels of different sizes so that the tool may be used to bend tubes of various diameters. For removably securing a mandrel to the gear, the latter is provided with a notch 16 on its upper surface in which is secured an elongated key 17 engageable with a recess portion 18 formed on a mandrel 19 placed over the gear to provide a driving connection between the gear and mandrel. The shaft 14 is provided with an upper portion 20 somewhat further reduced in diameter and threaded at 21 to engage the internal threads formed in a cap member 22 which serves to hold the mandrel in place over the gear.

The mandrel 19 is of usual construction having a pcnite States Patent 0 riphera'l groove 23 therein and a flat face 24' to which is pivotally secured a hook 25 adapted to engage a tube 26 placed in the tool for bending.

Cooperating with the groove 23 formed in the mandrel is a shoe member 28 provided with a groove 27. It will be noted that the grooves in the shoe and mandrel are semi-circular in cross section so as to form, when placed in adjacent cooperative relationship, a substantially cylindrical opening to engage the tube.

As mandrels of different sizes require the use of shoes of different sizes, means are provided for readily interchanging shoes. To this end, the shoe is removably held by a shoe holding member 30, which, as best shown in Figs. 4 and 5, is provided with a substantially rectangular base portion 31 having a pair of parallel elongated slots 32 formed on opposite sides thereof. The shoe holding member 30 is slidable toward and away from the gear properly to position the shoe and mandrel in cooperative relationship. To provide a long wearing surface slidably supporting the shoe holding member, the top of the body member adjacent the shoe holding member carries a flat steel plate 33 having a rectangular groove 34 formed therein. Secured to the plate on opposite sides of the groove is a pair of side plates 35, each preferably made of steel and having their edge portions 36 engaging the slots 32. and extending over the groove to form therewith a dovetail slot to hold the shoe holding member in place. The shoe holding member is preferably also made of steel although, if desired further to lighten the weight of the tool, the shoe holding member may be provided with a steel base plate slidable in the slot.

To secure the shoe holding member in adjusted position on the base member, the plate 33- is provided with a plurality of holes 38 spaced along the bottom of the groove 34 each engageable by a pin 37 slidably carried by the body member. To this end there is provided an opening 38:; in the body member having internal threads engaging the threads formed on the bottom of a hollow post 39. The hollow in the post is aligned with the opening 38:: and encloses a spring 40 engaging the pin 37 constantly to urge the same downwardly into one of the holes 38. A manually operable knob 41 is secured to the upper end of the pin so that the same may be retracted from an opening, the entire shoe holding member slid in the slot and the pin reengaged with another one of the holes 38 to position a shoe held therein at the proper distance from the mandrel.

To adapt the shoe holding member to support any one of a plurality of shoes of different sizes in adjacent cooperative relationship with a mandrel of corresponding size secured to the gear, the portion of the shoe holding member adjacent the mandrel is provided with an over hanging portion 42 which defines therebeneath a U- shaped slot 43 which extends from side to side of the holding member. The portion is provided with an opening 44 which slidably supports a pin 45 insertable through a suitable opening 46 formed in the shoe 28 and into an opening 44a formed in the bottom of the shoe holding member. The pin 45 is provided with an elongated slot 47 engageable by a pin 48 held in the upper portion 43 so as to prevent the pin from dropping out of the tool. By merely raising the pin 45 the shoe 28 may be removed and replaced with another shoe similarly constructed except for the radius of the groove 27.

From the part of the tool thus far described it will be clear that mandrels and shoes of different sizes may be used. To change the mandrels it is merely necessary to unloosen the cap 22 and lift the mandrel off the post 20 .whereupon it can be replaced by a second mandrel, for

example, such as the mandrel 50 shown in Fig. 3, which latter mandrel is provided with a suitable recess 18 to engage the key 17 on the gear and is held thereon by the cap member. Similarly it is possible to replace the shoe 28, as for example by the shoe 51 shown in Fig. 3, the latter shoe being provided with an opening 46 corresponding in size to the opening 46 shown on the shoe 28.

For rotating the gear 15 which carries the mandrel there is provided a worm 53 secured to a shaft 54. The worm is mounted in an opening 55 formed in a U- shaped member 56 secured to the body member and provided with bearing surfaces 57 and 58 which rotatably support suitably reduced portions 59 and 60 of the shaft so as to retain the shaft against longitudinal movement. Adjacent the opposite end of the body member the shaft is supported by an arm 61 secured to the body member and carrying a bearing 62 for the shaft. A suitable handle 63 is secured to the shaft so the same may be rotated to rotate the worm and gear.

When a tube is placed within the generally cylindrical opening formed by the cooperating grooves on the mandrel and shoe and thehook 25 is placed over the tube as shown in Fig. 1, rotation of the handle 63 produces rotation of the worm, gear and mandrel to draw the tube around the mandrel to the position shown in dotted lines in Fig. 'l and produce therein the desired bend. If a firm support for the tube bending tool is desired the latter may be placed in a vise or other suitable device and for this purpose the body member is provided along each side with parallel cutout portions 64. As the operator of the tube may shift his grip on the handle during the bending operation, or in the event he is unable to maintain a constant pressure on the handle, no backlash or reverse rotation of the gear and mandrel can occur through the worm shown. Thus even though pressure on the handle be varied or even removed during the bending operation reverse rotation will not occur and thus the hook 25 will not release its grip of the tube. As previously pointed out, this feature is particularly important when bending tubes of resilient material.

To retain the shoe holding member 30 in position in the groove 34, a pin 70 is pressed into a suitable opening formed in the bottom of the groove after the tool has been assembled. To insert a tube to be bent into the tool, the pin 37 may be raised against the tension of the spring 40 and the tool holding member slid outwardly toward the stop pin 70 to separate the shoe and mandrel. A tube may then be inserted between the shoe and the mandrel and the shoe holding member slid inwardly until the shoe carried thereby abuts the tube at which time the pin 37 may be released to slide into one of the holes 38 in the bottom of the groove to retain the shoe holding member in proper position relative to the mandrel and to the tube to be bent.

I claim:

1. In a tube bending tool, a body member rotatably carrying a mandrel and having a way extending radially of the mandrel, means cooperable with the mandrel to form a tube bending orifice comprising a shoe holding member mounted in the way for sliding movement toward and away from the mandrel, means for securing any one of a plurality of shoes of different sizes to the shoe holding member, and means for securing the shoe holding member to the body member in a limited num- 4 her of positions each differently spaced from the axis of rotation of the mandrel to position a shoe held therein in juxtaposed tube guiding coperative relationship with the mandrel.

2. In a tube bending tool having a body member rotatably to carry a mandrel, means cooperable with the mandrel to form a tube bending orifice comprising a slot formed in the body member and extending radially of the axis of rotation of the mandrel, a shoe holding member having a portion slidably engaging the slot, means for securing any one of a plurality of shoes of different sizes to the shoe holding member, and a pin mounted on the shoe holding member and movable into engagement with any one of a plurality of holes formed along the bottom of the slot to secure the shoe holding member to the body member in any one of a plurality of positions each differently spaced from the axis of rotation of the mandrel to position a shoe held therein in juxtaposed tube guiding cooperative relationship with the mandrel.

3. In a tube bending tool having a substantially rectangular body member of aluminum alloy rotatably supporting a mandrel, means cooperable with the mandrel to form a tube bending orifice comprising a steel plate secured to one face of the body member and provided with a groove extending radially of the axis of the rotation of the mandrel, a pair of steel plates secured in spaced parallel relationship to the first-mentioned plate and each having an edge extending over the groove to form therewith a slot, a shoe holding member having a portion slidably engaging the slot and a portion spaced above the body member and extending toward the mandrel, a pin carried by the last-mentioned portion of the shoe holding member and movable downwardly to engage an opening in any one of a plurality of shoes of different sizes removably to secure a shoe to the shoe holding member, and a second pin mounted on the shoe holding member and movable into engagement with any one of a plurality of holes formed along the bottom of the slot to secure the shoe holding member to the body member in any one of a plurality of positions each differently spaced from the axis of rotation of the mandrel to position a shoe held therein in juxtaposed tube guiding cooperative relationship with the mandrel.

References Cited in the file of this patent UNITED STATES PATENTS 397,712 Fowler Feb. 12, 1889 578,416 Nielson Mar. 9, 1897 655,259 Miller Aug. 7, 1900 807,854 Neuert Dec. 19, 1905 842,111 Pedrick Jan. 22, 1907 1,060,461 Klarwasser Apr. 29, 1913 2,171,907 Beehler et al Sept. 5, 1939 2,466,381 Clouse Apr. 5, 1949 FOREIGN PATENTS 11,648 Great Britain of 1847 231,836 Germany Mar. 2, 1911 236,430 Switzerland June 16, 1945 925,027 France Mar. 24, 1947 

